With the development of manufacturing, integration and packaging technologies of semiconductor chips, electronic systems are gradually trending to have multi functions, high performance and high reliability. A system-level packaging method is developed to encapsulate components with different functions into a single package to provide different functions. The components with different functions may include active components, passive components, MEMS, optical components, etc.
A system-level chip package can be used as a final electronic product or a standard unit to be mounted on a PCB (Printed Circuit Board). Compared with a conventional chip package, the system-level chip package can be used not only in digital systems, but also in optical communication, sensor, MEMS, etc. Therefore, the system-level chip package can be widely used in fields of computer, automation, communication, etc.
A wire bonding technology is adapted in the conventional system-level packaging method to electrically connect pads of different chips using metal wires. Alternatively, in the conventional system-level packaging method, two chips may be electrically connected after their surfaces with pads are bonded face to face. However, processes of the conventional packaging method are complex.